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Reader SternisheFan links to a press release at UCLA, and excerpts from it another bit of Mars news: "For years, many scientists had thought that plate tectonics existed nowhere in our solar system but on Earth. Now, a UCLA scientist has discovered that the geological phenomenon, which involves the movement of huge crustal plates beneath a planet's surface, also exists on Mars. 'Mars is at a primitive stage of plate tectonics. It gives us a glimpse of how the early Earth may have looked and may help us understand how plate tectonics began on Earth,' said An Yin, a UCLA professor of Earth and space sciences and the sole author of the new research."

...for the followup papers by other scientists examining his findings before I make a conclusion. I have a friend who actually is a planetary geologist and focuses most of his attention on Mars, and I haven't heard any of this from him.

That was just the obligatory press release by UCLA. The peer reviewed version is here (paywalled): http://lithosphere.gsapubs.org/content/4/4/286.short?rss=1&amp%3bssource=mfr

After reading the original article it doesn't seem to clinch the case as much as the press release would have you believe. Several plate tectonics like mechanisms have been proposed for both Mars and Valles Marineris previously.

Yea, this is basically self-published by the school, rather than going through a journal publishing process. Regardless, it looks obvious

"You don't see these features anywhere else on other planets in our solar system, other than Earth and Mars," said Yin, whose research is featured as the cover story in the August issue of the journal Lithosphere.

I always found it odd that Mars' southern hemisphere would be so much higher than the northern one. This discovery means it might be simply a supercontinent that will be, in spite of its size, a transient[*] feature.

I'd like to hop on a time machine, go forward 200 years and read up a book on the geology of Mars. I wonder if they'll name previous continents (assuming they can be determined) by a system that uses names from famous Mars-related stories. The first bunch of continents named after features in the John Carter of Mars stories, another bunch taken straight from Bradbury's Martian Chronicles, et cetera.

I've been working on a time machine. I've got it to the stage where it can make small jumps into the future. Right now it can go one minute ahead. You just get in, sit in the chair, and press the button. It's not (yet) instantaneous, though. It takes about 60 seconds to complete the trip. I just need some more funding. Look for my kickstarter project soon. If it passes the $100K level I'll put in a more comfortable chair, which would open the way to longer journeys.

Why not just support human life extension research? Or at least human reversible hibernation... Time travel is not possible.

Of course it's possible, but only forward, and only at the rate of 1 second per second.

Well, you can go forwards as much as you like, up to a limit since your craft can never reach light speed since it has mass. Just accelerate in an arc away from the earth at a constant 1 or 2 G on a trajectory that will eventually bring you back to the start for 10 years. When you land you've travelled much more than 10 years into the future.

Because this kind of research 1% highly speculative, unlikely to be developed in my lifetime technology, although one that could be the greatest single technological advance ever, and the other 99% is bullshit sold by con artists

And here's the key: I'm not sure I'm qualified to tell the difference between the two.

You can orbit a super-massive black hole (like the one at the galactic center) and slow down time significantly.... but at the cost of not just massive exposure to radiation but also tidal forces that would rip your legs and head off your body even while technically outside of the event horizon (thus still in theory capable of leaving).

Travel at 99.9x% of the speed of light has other similar health risks where the background cosmic radiation can through blue shifts in frequency turn into deadly radiation...

I would guess the exact opposite. What I've read is that the theory is that Mars lost its atmosphere and electromagnetic field due to the core of Mars cooling and solidifying. IIRC it's core stopped spinning or slowed as well.

Shouldn't this mean that as Mars ages tectonics slow to a halt? For example, if the layers under the Earth's crust cooled, solidified and stopped rotating, isn't the theory that Earth will end up looking a lot like Mars in the far away future?

My thought exactly. I mean I'm not a geologist, but you'd sort of expect that the "largest volcano in the solar system" wasn't powered by an isolated puddle of magma. But ok, I realize there's a difference between proving something and speculating about it. They still won't get me to read the article though.

Like I said, I'm no geologist. But surely the much lower gravity and atmospheric pressure has a lot to do with the size as well. Not the same popping a champagne cork at sea level and at the top of Mt. Everest, assuming you can keep the damned thing in at that altitude. I wonder how densely packed that big mountain is, compared to say - Earth.

Actually, I've usually heard Olympus Mons mentioned as evidence against plate techtonics. It was created by a hot-spot, like the Hawaiian islands, but the reason it's so big is that the plates aren't moving, so the hot-spot stayed in the same place the whole time. If the Pacific plate weren't moving, there would only be one Hawaiian island, and it would be much bigger!

Whoops, I misread the post I replied to. We're obviously actually in agreement. Still, I hope I explained the mechanism involved a little better for people who may have been confused by the original post.

Let's not forget the little round ball that has volanoes spewing liquid nitrogen all over the place.In fact, any planet near a gas giant is almost certainly going to have tectonics of some sort because of the field strengths involved.Those planets get stretched constantly.

There are a lot of little round balls out there. And even more little not-so-round balls. And some very large and quite round balls. A little more precision would be helpful. It might even improve your miserable self-esteem to the point that you can bear to be identified by your posts.

What the hell happened to Venus? It's about 80 percent of the earth's mass. Why on Venus wouldn't it have a plate tectonics? Just because you can't see it happen doesn't mean it's not there.

Because it does not have tidal forces from a large nearby moon tugging on it like Earth does.

The solar tide on Venus is nearly as strong as the lunar tide on Earth. The planets are close to the same size and density so they probably have close to the same composition. Therefore they must have close to the same heating due to nuclear decay. Nearly the same tidal force. There is no doubt a difference in surface rock composition due to the lack of liquid water.

I never realized that solar tides are so strong, and of course they would be stronger on Venus than Earth. And it does make sense that the tidal effects on liquid water are going to have a much more dynamic effect on a planet than those that just affect solid rock. Thank you for helping educate me.

Yeah it does. I didn't think of that. It rotates 240x slower than the Earth. I figure the amount of energy released by the tidal effect is probably about proportional to the square of the rate of rotation, so tidal heating would be very little compared to Earth even though the tidal force is almost as strong. Most of its core heat, of which it apparently has a lot since it seems to have been recently resurfaced by supervolcanoes, must come from radioactivity.

Most of the energy the Earth receives is dissipated in the oceans. Very little is used to heat the interior. Back when the Moon was much closer to the Earth, the tidal heating on both bodies would have been more significant, but the Moon has receded so far away that it's not that important now.

The bulk of the Earth's (and Venus's) internal heating is the result of the decay of long-lived radioactive isotopes in the mantle (K, U, Th), and heat leftover from the accretion and differentiation processes. Ass

So, Mars is like Earth. Kind of "normal". The day takes about same amount of time and tilt is similar. Mars is kind of like a twin of Earth. And since there is evidence for water on Mars in the past (back when it had a magnetic field), tectonic plates are kind of expected.

Of course *now*, that tectonic activity may have stopped. There is no evidence for recent tectonic activity on Mars. Mars lost its water and atmosphere to space, mainly due to collapsed magnetic field. The planet is just too small to carry on the "dynamo" going for 4,000,000,000 years. 2,000,000,000 years ago, Mars could be with liquid water and maybe even breathable atmosphere.

As to Venus, well, its axis tilt is fucked. It is spinning the "wrong way" (opposite of other planets). Something big rolled over Venus long time ago, bit enough to make it spin the other way. Maybe it never recovered from that event. And since Venus now has no tectonic activity (observed via a Magellan)

it can't remove its CO2 from atmosphere, and well, that is causing problems. Like being the hottest place in the solar system. Current understand of tectonic plates require water to "push" one planet beneath another. On Venus, there is evidence that internal pressure is causing some parts to go up and some down, but there is insufficient height differential to force one plate under another and no water to fill in the holes and move the "low" areas lower. So you end up with no tectonic plates.

As to an example of another planet that got reamed by something large, it would be Uranus. It has axis tilt of about 90 degrees

So, four out of the classical nine planets (Venus, Earth, Uranus, Pluto) got "fucked over" by something late in their formation, leading to double-planets/ giant moons (Earth-Moon ; Pluto-Charon) or high axial tilts (Venus, Uranus).

Four out of nine is nearly a majority, isn't it?

Breaking News! Mercury has been mantle stripped. It's over-dense for it's size, and looks like the core of a somewhat larger terrestrial planet which has had much of it's mantle torn off. Which is one of the things that a giant i

It certainly has lava flows (from the radar data mentioned elsewhere). It has volcano-like (though not very like Earth volcanos) structures. But there's very little evidence for current activity. On the other hand, crater counts (even accounting for the much thicker atmosphere) suggest that the visible surface is all younger than the average of the Earth's continents. But on the gripping hand, older than the average of the Earth's oceans.

That's not that astounding of a claim to make. There are only a handful of antes in our solar system that are rocky, and there wasn't necessarily evidence to support plate tectonics on those other planets. Now, if the claim had been that there weren't plate tectonics anywhere else in the galaxy, then yes, that would be quite a bold claim.

Because in serious science, being wrong is not a crime. In fact, the first person to state "we have no evidence for X, so we must assume it does not exist" often get's the credit for setting some student or other off to prove him wrong. Just remember, the true crime is being "not even wrong". Try to be wrong at least once a day; then you might learn something. The only condition is that you have to realise that you were wrong.

While the existence of tectonics on Mars is interesting in its own right, the really fascinating question is whether it is still continuing today. Yin seems to jump to the conclusion that it does without much data to back it up. I would like to see some measurements examining Martian tectonic movements. It shouldn't be that hard, we can already do that with centimeter precision here on Earth. If Mars turns out to be tectonically active, that would mean it still has a hot liquid mantle and it's not the cold dead planet we tought it was.

The reason why we have precise measurements is because we have 30 satellites in extremely precise orbits that are carefully measured and corrected, which broadcast GPS signals all day long. There is really no practical way of getting a system like that in place now or in the foreseeable future on Mars.

The reason why we have precise measurements is because we have 30 satellites in extremely precise orbits that are carefully measured and corrected, which broadcast GPS signals all day long. There is really no practical way of getting a system like that in place now or in the foreseeable future on Mars.

It probably wouldn't be that hard to get a system with LORAN level [wikipedia.org] resolution now. There's just no use for it. Any rovers around now can just use existing Mars orbiters to get a position.

Forgive me, IANAPG but didnt Mars cease to be geologically active long ago. Which is why we see no active volcanoes and very little atmosphere (no shielding from solar winds). Also, if earth is the only planet with active tectonics why is Venus literally covered with active volcanoes and an atmosphere thousands of times denser than earth?

Forgive me, IANAPG but didnt Mars cease to be geologically active long ago.

That's what we thought, which makes this finding surprising.

Also, if earth is the only planet with active tectonics why is Venus literally covered with active volcanoes and an atmosphere thousands of times denser than earth?

It's literally covered with active volcanoes, rather than having them occur largely along narrow zones near fault lines, precisely because it appears to lack plate tectonics, which would cause it to vent its internal heat more like Earth does rather than it's peculiar Venusian way...

Hasn't it long been assumed that Mars had plate tectonics in the past? Because it's a smaller planet and lacks a large moon, its mantle has cooled and plate tectonics has stopped. Then its core cooled, its magnetic field weakened, and its atmosphere was blown off by solar wind...

About a decade ago, magnetometry produced weak evidence for magnetic "striping" running more-or-less parallel to the (present) Martian equator. That certainly stimulated much thinking about the tectonics of Mars (plate tectonics, overturn tectonics, hotspot tectonics?). But that's an open debate on a changing evidence base, not an assumption.

The elevation map showing the alleged "split" crater in the valley is not very convincing. Is there other evidence that the two halves are really a crater, or is the claimant over-matching faint patterns?

Over-matching faint patterns has a long track record with Mars, where they used to "see" linear canals thru Earth telescopes. Turned out to be observers who were over-connecting the dots.

It doesn't convince me either. Looking at the video [youtube.com] (linked to from the original article)it looks as if his thesis is more about the effects of basally-detached slabs (subduction from a spreading centre in the region of the Tharsis volcanos?) generating "V-shaped" fault patterns. But that would have the sense of movement on Vallis Marineris in the opposite sense to what is marked on the press-release.

I'm not going to hold my breath looking to see what actually comes out of this. Looks like a pretty poor pr

I'm also a planetary geophysicist and generally agree with your assessment. I also note that the author is a terrestrial geologist. This is as far as I can tell, his first foray into planetary science, and so he may not be so familiar with the planetary literature. Plate tectonics has previously been hypothesized on Mars (Sleep, 1994) [agu.org]. The press release suggests that somehow, for forty years, no one has seriously looked at Valles Marineris. It clearly has a tectonic origin, but I don't see evidence for plat

If , as is generally agreed, Mars is somewhat older than Earth, and was stripped of it's atmosphere and lost it's magnetic core in it's death throes, then it's plate tectonics wouldn't be at a "primitive" stage, but an advanced state of entropy, essentially.. having slowed down due to cooling of the interior of the planet.. Since it's generally conceded that the first two conditions on Mars occurred, then what kind of scientist would compare the third condition (plate tectonics) to an *early* stage? It's lu